Self-cleaning venting orifice



W. K. HEILAND SELF- CLEANING VENT ING ORIFICE March 4, 1969 I of 2 Sheet Filed March 19, 1968 INVENTOR WOLFGANG K. HEILAND ATTORNEY March 4, 1969 w. K. HEILAND SELF-CLEANING VENTING ORIFICE z of 2 Sheet Filed March 19, 1968 WOC O O O O ,INVENTOR WOLFGANG K. HElLAND ATTORNEY United States Patent Ofl ice Patented Mar. 4, 1969 9 Claims ABSTRACT OF THE DISCLOSURE A tubular shaped self-cleaning device for venting fluids and gases between two different pressure potentials comprised of an outer housing, an inner housing, a piston and a compression spring. Secured to the forward end of the inner wall of the outer housing are a plurality of axial, inwardly-extending teeth which align and mate with longitudinal slots on the piston. When these slots are open the compression spring holds the piston in the fully forward position providing a path for fluids or gases to enter the elongated inner housing through perforations in its tubular wall and escape through an orifice outlet at the rear of the inner housing. When the slots are clogged with solid particles, the external pressure overcomes the force of the compression spring and the piston slides to the rear of the housing, thereby automatically cleaning the slots of accumulated material.

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world and for all purposes of the United States Government, with the power to grant sublicenses for such purposes is hereby granted to the Government of the United States of America.

This invention relates to an apparatus for venting gases or liquids containing entrained solid particles through an orifice between two different pressure potentials and more specifically to an apparatus for venting steam through the lid of a puffing gun. Venting of the steam in a pufiing process is very important because it greatly influences the speed and efficiency with which pieces of comestibles are heated.

An orifice, or orifice housing made of perforated or screening material will become plugged if a considerable amount of gas or liquid is vented through it. Once the perforations start to become plugged, the plugging progresses at an ever increasing rate because the velocity of the flow thru the remaining perforations increases until all the perforations are clogged and the flow stops. Since clogging of the outlet can impede or stop the venting operation at any time during the heating cycle, the material being processed is not heated to the same extent and this results in non-uniformity of the end-product. Furthermore, the orifice housing must be manually cleaned between each batch.

Unlike the stationary orifice housing, the orifice of this invention provides venting during the entire processing time and does not have to be cleaned between batches. When clogging occurs, the orifice housing of this invention cleans itself instantaneously with a swift piston stroke that hardly interrupts the flow of steam through the orifice. It is an essential function of this invention that once the housing is clogged, a complete cleaning stroke must be made before venting is resumed.

An object of this invention is to provide an efficient and continual means of venting gases or liquids through an orifice between two different pressure potentials.

Another object of this invention is to provide a device through which venting of gases or liquids is continual while the apparatus to which the device is attached is in operation.

A further object of this invention is to provide a selfcleaning orifice housing.

Still another object is to provide continual venting for a pufling gun so that all the pieces of comestibles will be heated to the same degree and the end-product will be uniform.

According to this invention, the foregoing objects are accomplished by a tubular shaped device comprised of a stationary, hollow cylindrical housing means, a stationary, elongated tubular fluid and gas conducting means, a cylindrical pressure responsive slidable means and a pressure yieldable resilient means. The stationary hollow cylindrical housing means is provided with (1) a plurality of cleaning means rigidly secured on the inside wall at its forward or high pressure end (that end which passes through a barrier separating a high pressure area from a surrounding low pressure area), (2) means for securing the stationary housing pressure tight into an opening in the aforementioned barrier, said means being located immediately adjacent to the high pressure end of the housing, and (3) means for securing the low-pressure end of the housing to a cover means. The stationary, elongated fluid conducting means is rigidly secured through a central radial opening in the cover means, the diameter of the opening being smaller than the inside diameter of the cylindrical housing. Access to and egress from the inner chambers of the fluid conducting means is provided by a plurality of axially disposed perforations on its tubular wall and by an orifice outlet at its low pressure end. The forward portion of the fluid conducting means is smaller in diameter than the rear portion thus forming a shoulder at the point of dimension change to provide a stop for a pressure yieldable resilient means which slips over and coils around the forward portion of the tubular fluid conducting means. The resilient means allows a pres sure differential to actuate a cylindrical pressure responsive slidable means having an internal diameter slightly larger than the external diameter of the rear portion of the fluid conducting means, the slidable means being slipfitted over the fluid conducting means in such a manner that its inner surface is in slidable contact with the rear portion of the fluid conducting means and its outer surface is in slidable contact with the inner wall of the housing means.

The pressure responsive slidable means is provided with a plurality of longitudinal slots which align and mate with the aforementioned cleaning means at the high pressure end of the housing means and provide access to the tubular fluid conducting means. A stop means secured to the forward end of the fluid conducting member limits the forward movement of the pressure responsive slidable means thereby preventing the cleaning means on the cylindrical housing from being hammered by the slot ends of the slidable means. An interchangeable orifice secured into the outlet end of the fluid conducting member provides means for controlling the volume of flow from the high pressure zone to the low pressure zone.

Referring to the drawings:

'FIG. 1 is a view of the assembled device while fully venting, shown partially in side elevation and partially in longitudinal cross section.

FIG. 2 is a view of the assembled device with the piston partially retracted during a cleaning stroke. This view is also partially in side elevation and partially in longitudinal cross section.

FIG. 3 is an end view from the front of the inner housing after it has been attached to the cap.

FIG. 4 is a view partially in cross section of the inner housing at line 4-'4 on FIG. 3.

FIG. 5 is an end view from the front of the outer housing.

FIG. 6 is a view partially in cross section of the outer housing at line 66 on FIG. 5.

FIG. 7 is an end view of the piston as seen from the front.

FIG. 8 is a view in cross section of the piston at line 88 on FIG. 7.

FIG. 9 is an end view of the pressure end of the complete assembly of FIG. 1.

The self-cleaning orifice housing consists of 4 major items: An outer housing 1, an inner housing 2, a piston 3 and a compression spring 4. The outer housing 1, threaded pressure tight from the outside into the wall of the pressure chamber lid -5 of a puffing gun, is equipped with a number of teeth 6, as shown in detail in FIGS. 5 and 6. Mating with teeth 6 on outer housing 1 are longitudinal slots 7 in the tubular part of piston 3, as shown in detail in FIG. 7. Rigidly supported by threaded cap 8 is inner housing 2. While slots 7 are open, most of the steam is vented through orifice 9, as shown by the arrow in FIGURE 1 and the pressure inside the piston 3 is about equal to the pressure in the pressure chamber. Under these conditions, the compression spring 4 holds piston 3 in the position shown in FIGURE 1, While longitudinal slots 7 are open and piston 3 is in the fully forward position as shown in FIGURE 1, steam escapes from the pressure chamber through slots 7 in piston 3, traverses the windings of spring 4 to enter inner housing 2 through openings 10 and 11, traverses inner housing 2 until it reaches chamber 12 from which it exits through openings 13 into space 14 between inner housing 2 and outer housing 1, enters rear chamber 15 of inner housing 2 through openings 16 and exits to the atmosphere through orifice 9. As longitudinal slots 7 become clogged, pressure inside piston 3 drops and the pressure in the pressure chamber overcomes the force of compression spring 4. As piston 3 moves back, teeth 6 comb slots 7 clean of all accumulated material. As soon as piston 3 moves back far enough to cover and close openings 13, the space 14 between outer housing 1 and inner housing 2 is cut ofl from the flow of steam from the pressure chamber of the puffing gun thus reducing the pressure in space 14 to that of the atmosphere. Piston 3 then moves back until it is fully retracted and the gas or stream from the pressure chamber enters inner housing 2 through openings 11 and fills the inside of piston 3 through openings 10 and 13. When the pressure inside piston 3 equals that in the pressure chamber, spring 4 pushes piston 3 forward and as soon as piston '3 has moved forward far enough to uncover openings 13 flow through orifice 9 is reestablished. Piston 3 moves fully forward to the position shown in FIGURE 1 and pressure equalization is maintained through longitudinal slots 7 as previously described. Full flow is maintained until longitudinal slots 7 are clogged again at which time the cleaning operation is repeated. Sealing between piston 3 and outer housing 1 is accomplished by ring seal 17 in conjunction with a loose sliding fit between piston 3 and outer housing 1, but no seal other than a tight slip fit is provided between piston =3 and inner housing 2. Forward movement of piston -3 is limited by machine screw 18 threaded into forward end of inner housing 2 thus preventing slot ends in piston 3 from hammering against teeth 6. The volume of flow through the device of this invention is controlled by the size of orifice 9 which can be varied by changing orifice plug 19 for a plug with an opening of the desired size. Orifice plug 19 is threaded into the rear of inner housing 2.

I claim:-

1. A self-cleaning venting device for allowing fluids containing entrained solid particles to escape from a high pressure zone to a low pressure zone, comprising:

(a) stationary tubular fluid conducting means connecting two zones having fluid under diflerent pressures including means for blocking the flow directly therethrough, said fluid containing entrained solid particles;

(b) stationary tubular housing means enclosing and supporting said stationary fluid conducting means; (c) pressure responsive slidable piston means mounted on said fluid conducting means and slidable within the housing means, said slidable means being provided with fluid-conducting passageways adapted to register with passageways on said stationary fluid conducting means and to form a continuous passageway connecting the zones of different pressure, thereby permitting the venting of fluid from the zone of higher pressure to the zone of lower pressure;

'(d) resilient means engaging between said stationary fluid conducting means and pressure responsive slidable means for normally maintaining the aforesaid passageways in register, and said resilient means being yieldable when said passageways become clogged and the higher pressure causes said slidable means to move out of register with the stationary fluid conducting means preventing fluid communication between two zones; and

(e) cleaning means mounted on the stationary housing adapted to engage the passageways in the slidable means, thereby to remove clogging solid particles.

2. A self-cleaning venting device for permitting fluids containing entrained solid particles to escape from a high pressure zone to a low pressure zone, comprising:

(a) a stationary, hollow, cylindrical housing adapted to be secured by a fluid-tight connection near one end to the low pressure side of a barrier separating a high pressure zone, containing a fluid having entrained solid particles, from a surrounding low pressure zone, the interior of the housing communicating with the high pressure zone;

(b) cleaning means rigidly secured to the inside of said housing adjacent the high pressure end;

(c) cover means secured across the end of the cylindrical housing remote from the end secured to the barrier, said cover means being provided with a central radial opening of smaller diameter than the inside diameter of the housing;

(d) elongated tubular fluid conducting means rigidly secured near one end thereof in the radial opening of the cover means and extending coaxially with the cylindrical housing into the high pressure zone, said tubular means having in its wall a plurality of axially disposed perforations and means for blocking the flow directly therethrough;

(e) cylindrical pressure responsive piston means shorter in length than and slidably mounted on the tubular fluid conducting means, said piston means having axial fluid conducting passageways communicating with the perforations in the tubular fluid conducting means when said piston is in the high pressure zone and the passageways are not clogged;

(f) pressure yieldable resilient means coacting with the tubular fluid conducting means and the piston to normally maintain said piston in the high pressure zone, thereby to provide a continuous path for venting fluid from the high pressure zone to the low pressure zone until said axial fluid conducting passageways in the piston become clogged with entrained solid particles, whereupon the pressure in the high pressure zone exceeds that of the yieldable means causing said piston to slide along the tubular fluid conducting means, the cleaning means on the housing adapted to engage the clogged axial passageways on the piston and clean the same, thereby restoring equal fluid pressure on both sides of the piston and causing the resilient means to restore the piston to its fluid conducting position.

3. The venting device of claim 2 wherein the cleaning means on the housing comprises a plurality of axial, in-

wardly-extending teeth on the inner wall of the housing.

4. A self-cleaning venting device for continuously venting gases containing entrained solid particles, from a vessel in which the gases are under a pressure higher than that outside the vessel, said device comprising:

(a) a stationary, hollow, cylindrical housing having a low pressure end and a high pressure end, said housing being adapted to be inserted and secured by the high pressure end thereof in an opening in the wall of a vessel containing gas under pressure, substantially all of said housing extending outside the vessel;

(b) cover means secured over the low pressure end of the housing, said cover means having a central radial opening smaller than the diameter of the housing;

(c) a plurality of cleaning means on the inside wall of the housing at a high pressure end thereof;

((1) elongated tubular gas conducting means extending coaxially with the housing through the central open ing in the housing cover, past both the low and high pressure ends of said housing, and forming a gastight seal with the housing cover, said tubular gas conducting means having perforations in its walls and including means for blocking the flow directly therethrough;

(e) pressure responsive piston means on the tubular gas conducting means provided with cloggable passageways, said passageways, when not clogged, communicating with the interior of the vessel and with the perforated tubular gas conducting means thereby providing a continuous path for venting gases, said passageways, when clogged, causing pressure on the pressure responsive means to shift to a position in register with the cleaning means on the housing, said cleaning means being adapted to clean said passageways on said piston means; and

(f) resilient means on the tubular gas conducting means and cooperating with the pressure responsive means to maintain the latter in a position for continuous venting when the passageways in the pressure responsive means are not clogged.

5. The device of claim 4 wherein the cleaning means on the housing comprises a plurality of axial, inwardlyextending teeth on the inner wall of the housing, and the pressure responsive means and provided with a plurality of axial, gas-conducting slots registerable with the teeth on the inner wall of the housing.

6. A self-cleaning venting device for continuously venting to the atmosphere gases containing entrained solid particles from a vessel in which the gases are under superatmospheric pressure, said device comprising:

(a) a cylindrical housing having open forward and rear ends;

(b) means for securing the forward end of the housing in an opening in a wall of a vessel and to form a gas-tight seal therewith, said forward end communicating with the interior of the vessel when secured thereto;

(c) pressure tight cover means over the rear end of the housing, said cover means having a central, radial opening substantially smaller than the diameter of the housing;

(d) cleaning means on the inner wall of the cylindrical housing adjacent the forward end thereof;

(e) a perforated gas-conducting tube longer than the cylindrical housing extending coaxially through the cylindrical housing and through the opening in the pressure-tight cover, said tube being rigidly secured to said cover by a pressure-tight seal, the portion of the tube extending outside the housing past the cover constituting a venting orifice, said conducting tube including means for preventing the flow directly therethrough;

(f) an elongated cylindrical piston, shorter than the gas-conducting tube, coaxial therewith, and having an inner surface in slidable contact with a portion of said gas conducting-tube and an outer surface in slidable contact with the inner wall of the cylindrical housing, the piston further having a plurality of longitudinal, axial passageways extending through its walls whereby, when the piston is in the extreme forward position, said axial passageways together with the perforations and bore of the tubular gas-conducting tube forming a continuous path for venting gases from the interior of the vessel to the atmosphere through the orifice, said cleaning means being adapted to clean said passages; and

(g) resilient means suflicient to normally maintain the piston in the extreme forward position as long as the axial passageways remain unclogged, and adapted to allow retraction of said piston when said passages become clogged.

7. The venting device of claim 6 wherein the cleaning means on the cylindrical housing comprises a plurality of axial, inwardly-extending teeth so disposed as to be registerable with the axial slots in the piston.

8. The venting device of claim wherein:

(a) the tubular gas-conducting means comprises an (b) the inner wall of the cylindrical housing and the outer wall of the tubular member together define an annular chamber communicating with both the forward :and rear tubular chambers;

(c) the cylindrical piston, when the longitudinal passageways thereof are not clogged, being maintained in an extreme forward position by said resilient means such that a continuous path for venting gas is provided, respectively, through said longitudinal passageways into the forward tubular chamber through the perforations therein, to the aforesaid annular chamber, to the rear tubular chamber, and finally to the orifice; and

(d) the resilient means being yieldable and adapted to cause the cylindrical piston, when the longitudinal passageways thereof are clogged forced rearward by pressure within the vessel to a position inside the annular housing whereby a portion of the perforations in the tubular member are covered, thereby breaking communication between the forward and rear tubular chambers thereof and bringing the clogged passageways into register with the cleaning means on the cylindrical housing.

9. A device for continually venting fluids from an apparatus through an orifice between zones of different pressure, said device comprising:

(a) a tubular housing having a plurality of teeth at the forward end thereof, means for threading the forward end of said housing pressure tight into the apparatus to be vented, and a cap forming a pressure tight cover on the rear end of the housing;

(b) a tubular fluid conducting member attached to,

rigidly supported by the aforementioned cap and extending therethrough, said member providing access to and egress from inner chambers thereof by means of a plurality of openings in the wall of said fluid conducting member, said fluid conducting member being provided with means preventing flow directly therethrough;

(c) an interchangeable orifice threaded into the outlet end of the aforesaid fluid conducting member;

(d) a slidable hollow piston having an internal diamconducting member to limit forward movement of eter such that when said piston is fitted over the rear aforesaid piston beyond said forward end. portion of said fluid conducting member no seal is needed between said piston and rear portion of said References Clted fluid conducting member and said piston is free to 5 UNITED STATES PATENTS move longitudinally over the surface of said fluid conducting member, said piston having a plurality of 1 i Waaser 137-244 Jonsson 55--289 longitudinal slots extendmg through a tubular por- 2189 361 2/1940 H o 55 312 tion of said piston providing access to the aforesaid 2131936 10/1938 ggg g fluid conducting member, said longitudinal slots being m 2,279,868 4/1942 Hayden 99238 in alignment with the aforementioned teeth on the aforesaid housing, said teeth being adapted to clean said HARRY B. THORNTON, Primary Examiner. (e) a compressron spring coiled around the outer surface of the forward portion of said fluid conducting 1 BERNARD NOZICK, Assistant Examinermember engageable between said piston and said fluid conducting member providing means for a pressure differential to actuate aforesaid piston; and 55 296, 310; 99--238; 220-44; 239107, 114 (f) stop means secured to the forward end of the fluid 3,025,005 3/1962 Daiforn et a1. 239-l17 

